Design of resonant cavity thin film structures with complex active layers

摘要

A systematic approach to designing resonant cavity distributed Bragg reflector (DBR) structures with complex-index active regions is developed in this paper. The technique is based on the effective reflectance index of multilayer thin films. While the design of DBR structures with real refractive index films is quite straightforward, the use of a complex refractive index in the cavity requires a different approach. In this paper, we show that a complex active region requires an asymmetric reflector geometry along with a separate phase compensator. This technique is illustrated using phase change materials and metals in the resonant cavity. (C) 2020 Optical Society of America